1. Unit 4 Topic 1
SPDF

2. Principal Energy Levels
Electrons occupy principal energy levels around the nucleus of the atom
These energy levels represent specific distances from the nucleus.
Each energy level n = 1 to n = 7, is farther from the nucleus

3. Principal Energy Levels Cont
Each Principal Energy Level (n) has a specific number of electrons which are allowed to occupy that level.
A completely filled level is considered very stable.
The number of electrons allowed in each level is indicated below:

4. Principal E Level
Max # Electrons
Sublevel type
n = 1 2
1s only
n = 2 8
2s and 2p
n = 3
3s and 3p
n = 4 18
4s, 3d and 4p
n = 5
5s, 4d and 5p

5. Sublevels
Each principal energy level is divided up into sublevels (s, p, d & f)
The s and p sublevel electrons in the outermost energy level of an atom represent the valence electrons for a given element.
The same group (column) of the periodic table have the same number of valence electrons

6. This is just a picture of the orbitals. Aren’t these crazy looking
This is just a picture of the orbitals. Aren’t these crazy looking? This is why we just draw Bohr models even though we know they are not correct.

7. Sublevels continued
The maximum number of electrons allowed in each sublevel are as follows:
s = max 2 electrons
p = max 6 electrons
d = max 10 electrons
f = max 14 electrons

8. Structure of Periodic Table
The structure of the periodic table can be related to the electronic structure of the atom
Each row (period) corresponds to the principal energy levels in an atom
So if an element occupies the fourth row, then it has electrons occupying the first 3 energy levels being filled with the maximum number of electrons allowed for that level

9. Column (Group)
Each Column (group) corresponds to the sublevel being occupied by the atoms electrons:
Group 1 fills the first s orbital
Group 2 fills the second s orbital
Groups 3-12 fill the first d orbital through the tenth d orbital
Groups fill the first p orbital through the sixth d orbital (except for He)

10. Coloring the Orbitals
Create a Color/Pattern code and fill in the periodic table in your coloring book to depict the location of the different orbitals.
Label the Table and remember a CODE!

11. Electron Configurations2 s p 3 4 d 5 6 7 f
Electron Configurations

12. Valence Electrons
The electronic structure of the atom (and the periodic table) are used to determine the number of valence electrons in the atom of an element.
The valence electrons are the s and p orbitals in the outermost energy level occupied by electrons.
This allows you to keep track of them by the columns of the periodic table.

13. Fill out.. Fill out the Data table on your worksheet
The first one has been completed for you as an example.
Remember when you are doing the dot diagrams to place a dot on all four sides FIRST before pairing.

14. 1 ns1 +1 2 ns2 +2 13 ns2 np1 +3 14 ns2 np2 + or – 4 15 ns2 np3 -3 16
Group #
Electron Config
# Valence
Dot Diagram
Oxidation # 1
ns1 +1 2
ns2 +2 13
ns2 np1 +3 14
ns2 np2
+ or – 4 15
ns2 np3 -3 16
ns2 np4 -2 17
ns2 np5 -1 18
ns2 np6

15. Definitions Add these definitions into your vocab
Pauli Exclusion Principle – No more than two electrons can occupy a single orbital
Aufbau Principle – German word for “building up”. Electrons fill orbitals with lowest energy first.
Hund’s Rule – Orbitals must each occupy one electron before pairing. (Bus Rule)

16. Wolfgang Pauli Young Friederich Hund Old Friederich Hund
I threw this in there because you know how much I love my old scientists! ;)
Old Friederich Hund

17. The End!

18. 1s 2 s p 3 4 d 5 6 7 f

19. 1s 2 s p 3 4 d 5 6 7 f
Noble Gas Method : Put the noble gas representing the last filled energy principal level
in brackets [ ] and then list the rest of the electronic configuration
Example: Potassium (K) = [Ar] 4s1

21. 1s 2 s p 3 4 d 5

22. This is read from left to right, and top to bottom.
Example: Carbon: 1s2 2s2 2p2
Noble Gas Method : Put the noble gas representing the last filled energy principal level
in brackets [ ] and then list the rest of the electronic configuration
Example: Potassium (K) = [Ar] 4s1

23. Electronic Configurations Remember to use the SUPERSCRIPTS
Write out the electronic configurations for the following Elements:
Nitrogen :______________________________________
Helium:________________________________________
Lithium:________________________________________
Sulfur: ________________________________________
Chromium:_____________________________________
Write out the electronic configurations using the Nobel Gases Method
Zinc:__________________________________________
Rubidium:______________________________________
Chlorine:_______________________________________
Silver:_________________________________________
Magnesium:____________________________________